[Maas-devel] Node states

[Matthew Revell]

Hi,

Across different meetings there has been a common theme: uncertainty
over precisely what state a node can be in and what those states mean.

Here's my understanding of the states we need:

 * Declared: MaaS is aware of the node and has assigned it a system
ID, but has done nothing else to it. A declared node can return to
this state.
 * Testing: Smoke or burn-in tests are in process.
 * Bad: for a reason not covered by the sub-states, the node cannot be used.
  - Bad -- testing: smoke or burn-in testing has a found a problem.
  - Bad -- MIA:  the MaaS can't contact the node.
 * Ready: Testing has been done and the node is in the general pool
ready to be deployed.
 * Reserved: Testing has been done and the node is ready for named deployment.
 * Allocated: A node has been allocated to a specific user for their
exclusive use.
 * Deployed: The node has been deployed with either a fresh Ubuntu
install or a Juju charm.
 * Retired: The node has been removed from service until the MaaS
owner overrides the retirement.

The "Allocated" state is one we've discussed but is out of scope for 12.04.

The "Bad" states haven't really come up in conversation but they seem
to me to be necessary.

There is some fuzziness around "Retired": is a retired node one which
has been taken out of action manually, for whatever reasons, or is it
a node that was previously declared and has been torn down? From our
discussions in Budapest, the first of these makes most sense to me.
Also, I believe a deployed node simply becomes declared once it has
been torn down.

Thanks in advance for your comments.

--
Matthew Revell
Launchpad Product Manager
Canonical

https://launchpad.net/~matthew.revell